Radial penetrator assembly and method

ABSTRACT

Radial penetrator assembly  10  conducts fluid through the passageway in the wall to a wellhead housing  18  and into a port in a tubular hanger  14  positioned within a central bore  19  in the wellhead housing. The flexible tube  22  extends between the passageway in the wellhead housing and the port in the inner member, while sleeve-shaped adapter  30  extends radially from the wellhead housing and has an adapter bore sealed to a radial passageway in the wellhead housing. A radial outer seal  64  seals between the radial outer portion of the adapter  30  and a radially outer portion of the flexible tube  22 . The flexibility of the tube permits an inner portion axis with the tube to be offset or slanted with respect to an outer portion axis of the tube.

FIELD OF THE INVENTION

The present invention relates to a radial penetrator assembly and, moreparticularly, to a radial penetrator assembly with metal-to-metal sealsand a sleeve-shaped adapter extending radially from a wellhead housing.

BACKGROUND OF THE INVENTION

Some oilfield applications involve conducting high pressure fluidsthrough a tubing hanger, through a bridge across an annular gap, thenthrough an outer wellhead housing, such as a tubing spool or wellheadbody, with all critical seals being metal-to-metal seals. A conduit maybe attached to the inner body to seal internal pressure within theconduit, while the opposing outer end of the conduit may be sealed withthe outer wellhead housing. However, the two end attachments to whichthe conduit ends are affixed and pass through typically possess somemisalignment, either vertically or laterally (circumferentially). Pastpractice has typically employed small diameter OD, thin walled conduittubing that could easily be bent to compensate for any misalignment,while still maintaining sufficient straightness to achieve theconditions necessary to ensure that the pressure fittings could performtheir sealing functions at each end of the conduit. The conduit andfittings extending between the hanger and the outer wellhead housing arecommonly referred to as a radial penetrator, since the fluid is directedradially through the housing wall. Numerous patents have been directedto radial penetrator assemblies, including U.S. Pat. Nos. 6,047,776,6,050,338, 6,119,773, and 6,470,971, and many of the references cited inthese patents.

For a larger diameter, thicker walled conduit, the above methods workneither consistently nor well. It is much more difficult to bend largediameter, thick walled tubing, which begins to resemble small diameterpipe. Side loads sufficient to flex the pipe sideways to completemake-up of the fittings may cause the tube to assume an ellipticalshape, which makes it difficult to assure a reliable external seal.These side loads are also difficult to generate manually, as requiredfor field make-up operations.

Past practices include making up the first end fitting exiting from thetop of a tubing hanger with a pre-bent conduit which directs the flow toa substantially horizontal plane. Feedthrough of continuous conduits isconventionally through the tubing hanger axially, then the conduit maybe bent and manually fed through the wellhead wall. This fairlysimplistic and reliable operation conventionally may only beaccomplished with small diameter, thin-wall tubing with sufficientflexibility to manually bend the lines. Passage of the bent conduitthrough the wellhead wall from the outside may also require a very largeport through the wellhead wall. Substantial offsets, both vertically andlaterally, may occur and may be compensated for externally.

The disadvantage of the prior art are overcome by the present invention,and an improved radial penetrator assembly and method are hereinafterdisclosed.

SUMMARY OF THE INVENTION

A radial penetrator assembly is provided for sealingly conducting fluidthrough the passageway in a wall of a wellhead housing having a centralbore, with the fluid passing into a port in an inner member positionedwithin the central bore of the wellhead housing. The radial penetratorassembly includes a flexible tube extending radially between thepassageway in the wellhead housing in the port and the inner member, asleeve-shaped adapter extending radially from a wellhead housing to anadapter bore, sealed to the passageway in the wellhead housing, and aradially outer seal between a radially outer portion of the adapter andthe radially outer portion of a flexible tube, such that the flexibilityof the tube permits an inner portion axis of the tube to be axiallyoffset or slanted with respect to an outer portion axis of the tube. Ina suitable embodiment, the radially outer seal is a metal-to-metal sealbetween an outer sealing surface on the flexible tube of the innersealing surface on the adapter.

In one embodiment, the inner member may comprise of a tubular hanger forsuspending a tubular string in the well, and the port in the tubularhanger and a throughport which extends to an end surface of the tubularhanger. The radially alignment member may be used for selectivelyaligning the inner member with the central bore of the wellhead housing.A radial spacing between a radially inner end of a flexible tube and aradially outer end of a flexible tube preferably is in excess of about30% greater than the radial spacing between a radially inner end of theflexible tube and radially outer end of the passageway in the wall ofthe outer member.

A method of the invention includes radially extending the flexible tubebetween the passageway and the wellhead housing and the port in theinner member, and providing a sleeve-shaped adapter extending radiallyfrom the wellhead housing and having an adapter bore sealed to thepassageway of the wellhead housing. The radially outer seal is formedbetween a radially outer portion of the adapter and the radially outerportion of a flexible tube, such that the flexibility of the tubepermits an inner portion axis of the tube to be axially offset orslanted with respect to an outer portion axis of the tube.

A particular feature of the invention involves the use of seals suchthat test fluid may be introduced to verify the holding of a selectedworking pressure. This test operation may be performed at the surface,thereby providing assurance to the operator prior to downholeinstallation that the system will perform as intended.

A significant advantage of the present invention is that the techniqueis relatively simple and involves highly reliable and commerciallyavailable components.

These and further features and advantages of this invention will becomeapparent from the following detailed description, wherein reference ismade to the figures in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-6A illustrate the wellhead assembly during various stages ofinstallation.

FIG. 1 illustrates the wellhead housing with a tubing hanger above alanding shoulder, prior to being sealed within the bore of the wellheadhousing.

FIGS. 2 and 3 illustrate the wellhead housing with a tubing hanger in asubsequent stage of installation. FIG. 3A illustrates in greater detailthe radial penetrator assembly shown in FIG. 3.

FIG. 4 illustrates the wellhead housing with a tubing hanger in anotherstage of installation, while FIGS. 4A and 4B illustrate in greaterdetail, the radial penetrator assembly shown in FIG. 4.

FIG. 5 illustrates the radial penetrator in a wellhead housing inanother stage of installation.

FIG. 6 discloses the wellhead housing with a tubing hanger and a pair ofradial penetrators in another stage of installation, with the penetratorshown in greater detail in FIG. 6A.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A radial penetrator assembly as shown in detail in FIG. 5 may be usedfor sealingly conducting fluid through a passageway in a wall of awellhead housing 18, as shown in FIG. 6, with the wellhead housing 18conventionally having a central bore 19 and a lower end with a flange 17for sealing engagement with other oilfield equipment. The radialpenetrator assembly 10 as shown in FIG. 5 extends from the wellheadhousing 18 radially inward to an entrance/egress port 15 in an innermember, such as the tubular hanger 14 shown in FIG. 1, with a hanger 14having a throughport 16, conventionally extending downward to one ormore tubing lines 12 extending further downward through the wellheadhousing 18 and typically into the well. The interior of tubing 12 asshown in FIG. 6 is thus in sealed fluid communication with the radiallyoutward end 22 of the flexible tube 20, as shown in FIG. 5. The wellheadhousing 18 as shown in FIG. 1 may also have an inner cylindrical bore19. The tubular hanger 14, which acts as the inner member, may have agenerally cylindrical outer diameter.

The radial penetrator assembly of the present invention is particularlysuitable for providing the desired flow path between a wellhead housing18 and a tubular hanger for suspending a tubular string in a well. Inother embodiments, the tubular hanger may be replaced by a plug or otherinner member for landing in the central bore of the wellhead housing 18and having a port in general alignment with the radial passageway in thewall of the wellhead housing. The port may not continue through theinner member in a downward manner as shown for the tubular hanger, andinstead may extend axially upward from the port to a top surface of theplug, or may extend to some other surface of the inner member. Also, thepassageway in the wall of the wellhead housing may supply fluid to aport in an inner member which has no outlet, and instead may, forexample, supply an opening pressure or a closing pressure to a valvewithin the inner member 14. Also, it should be understood that the term“wellhead housing” as used herein refers to the outer housing or spoolof oilfield equipment which has a central bore for receiving the innermember and one or more passageways in the wall of the outer member eachfor receiving the radial penetrator assembly as disclosed herein.

A feature of the invention is that the various metal seals required forthe penetrator assembly are not formed by threads, and instead threadsare preferably used to removably attach and detach the radial penetratorassembly from the wellhead housing and the inner member. Also, theflexible tube which extends radially between the wellhead housing andthe throughport in the inner member is preferably of the type which hasa substantially fixed axial length, i.e., the flexible tube itself isnot constructed in a manner such that its axial length may be easilystretched or reduced in the manner of an elongate bellows. Highreliability and low cost are thus achieved with the uniform diametermetal flexible tube as disclosed herein, which may be fabricated fromsteel, inconel, copper, or other flexible yet high burst pressurematerial.

The radial penetrator assembly as disclosed herein preferably includesthree metal-to-metal seals which allows the assembly to be reliablyinstalled, easily removed, then again installed in the wellhead housingand the tubular hanger. As shown in FIG. 5, a first, inner seal isformed by the tapered nose 21 of tube 20 in contact with a contact seat32 in the tubing hanger body 14. This first, inner seal is energized andretained by the threaded gland 64. A second, radially intermediate seal,which optionally may be supplemented by an elastomeric seal 38, sealsbetween the inner portion of the adapter 30 and the wellhead housing 18.Finally, a third, outer metal-to-metal seal is energized by a threadedgland 66, sealing between the outer end of the adapter 30 and the outerend of the flexible tube 20. This construction allows a cover flange 52as shown in FIG. 6A to be easily installed, so that fluids may bereliably transmitted between the control or injection line 42 as shownin FIG. 6A and the flow line 12 as shown in FIG. 6.

The tubular hanger 14 as shown in FIG. 6 includes a central bore 24 influid communication with and extending above the bore 19 in the wellheadhousing 18. The upper end 25 of the tubular hanger 14 as shown in FIG. 2may be provided with one or more seals 26 for sealing engagement withthe lower end (not shown) of a tubular spool adapter which may bestabbed over the top of the tubing hanger and locked to the wellheadhousing 18.

Those skilled in the art will appreciate that the tubing hanger 14 asshown in FIG. 1 is shown raised from its landed position on the wellheadhousing, and has been landed on shoulder 28 of housing 18 in FIG. 2,with seals 29 providing a static seal between an outer diameter of thetubular hanger and an inner cylindrical bore of the wellhead housing.Once landed, the tubular hanger may be locked axially within thewellhead housing by a C-ring 85 which engages grooves provided in thewellhead housing. The upper end of the wellhead housing may also includeone or more outer grooves 88 for receiving a locking member tostructurally connect with the wellhead housing 18 with a tubing spooladapter (not shown) or other housing.

FIG. 2 illustrates a conventional threaded plug 87 secured to thetubular hanger 14 for closing off the throughport 15 in the hanger, andanother conventional threaded plug 89 secured to the wall of thewellhead housing to close off the radially extending passageway 88through the housing wall, as shown in FIG. 1. Still referring to FIG. 2,the radial penetrator assembly as disclosed herein convenientlyaccomplishes its desired goal of sealingly conducting fluid even thoughthe central axis 86 of the plug 87, and thus the central axis of thethroughport 15 in the tubular hanger, is not in alignment with thecentral axis 90 of the plug 89, and thus the central axis of the radialpassageway 88 in wellhead housing 18.

A suitable sequence for installing the radial penetrator assembly at thesurface may thus start with the assumption that the tubing hanger 14 hasalready landed on the shoulder 28 of the wellhead housing 18 as shown inFIG. 2, and that the axis 86 of the radially outer port in the outersurface of the tubular hanger may not be in precise alignment with theaxis 90 in the radial passageway in the wellhead housing.

Various forms of a conventional alignment members on one of the housingand tubing hanger may be used in cooperation with a groove on the otherof the wellhead housing and the tubing hanger to automatically align thetubing hanger 14 within the wellhead housing, so that the landed tubinghanger is properly positioned when lowered onto the shoulder 28. In mostcases, misalignment between the axes 86 and 90 as shown in FIG. 2 may beslight once the tubing hanger is properly landed on the wellheadhousing.—Even a slight misalignment may, however, make it difficult toobtain the desired metal-to-metal seals for fluid communication betweenthe one or more tubes 12 and the corresponding radial passageways in thewall of the wellhead housing 18.

Referring again to FIG. 5, the radial penetrator assembly 10 includesthree primary components. Elongate flexible tube 20 preferably has asubstantially uniform diameter outer surface 21 along substantially itsentire length. A generally sleeve-shaped adapter 30 is positioned withina passageway 88 of the wellhead housing 18, extending radially from thewellhead housing 18 to an adapter passageway 33 of the adapter 30. Theseal 38 seals the passageway 88 between the adapter 30 and the wellheadhousing 18. The flexibility of the tube 20 permits an inner portion axis92 of the tube 22 to be axially offset or slanted with respect to anouter portion axis 94 of the tube 20. More particularly, a re-sealablemetal-to-metal seal is preferably obtained between an outer sealingsurface of the flexible tube 20, which preferably is the outersubstantially uniform diameter cylindrical surface 21, and the innersealing surface 34 on the adapter 66, which energizes the seal. In apreferred embodiment, the inner threaded plug 64 as shown in FIG. 5 maybe threaded to the tubular hanger 14 to energize the seal between thetapered nose 21 of the flexible 20 and the contact seat 32 in the tubinghanger body 14. The threaded glands 64, 66 thus allow the adapterassembly to be easily installed between the tubular hanger, but alsoallow the adapter assembly to be easily removed. Thus, for example, thetubing hanger subsequently may be raised above the wellhead housingafter the seal assembly as shown in FIG. 2 has been retracted, therebyallowing the tubular suspended in the well from the tubing hanger 14 tobe retrieved through the wellhead housing 18.

Still referring to FIG. 5, it should be understood that the purpose ofthe adapter 30 is to lengthen the axial spacing between the threadedplugs 64 and 66 from that which would conventionally be provided if theinner plug 64 were between the inner end 65 between an outer end 22 ofthe tube 20 in the wellhead housing 18. More particularly, the axiallength of the adapter 30 is preferably controlled so that a radialspacing between a radially inner end 65 of a metal tube 22 and aradially outer end 67 of the metal tube is at least about 30% greaterthan the radial spacing between the radially inner end 65 of the tube 20and the radially outer end 95 (FIG. 3) of the passageway in the wall ofthe wellhead housing 18. Adapter 30 thus results in a substantialincrease in the length of the flexible tube 70, thereby providing theflexibility between the ends of the tube to achieve the desired sealingfunctions, as disclosed herein. In most applications, this radialspacing between the inner end of the tube will be about 30% or more, andin many applications at least about 40%, greater than the spacingbetween the end of the flexible tube and the outer end of the passagewayin the wall of the outer housing.

A tapered nose 21 of tube 20 and inner threaded gland 64 as shown inFIG. 3A may be installed with the centerline 72 of the threaded gland 64aligned with the cetnerline 92 of the throughport in the hanger 14. Thethreaded gland 64 may be tightened to the desired torque using asleeve-shaped threading tool 76 as shown in FIG. 3A that allows a deepenough reach to perform the task. Installation of the threaded gland 64and the tapered nose 21 of tube 20 may result in vertical and/or lateral(circumferential) offset of the centerline 92 with respect tot hecenterline 94, as shown in FIG. 5. Conventional wrench flats 77 on tool76 allow the tool and thus the inner socket end of the tool to make-upor break-out the threaded gland 64 from the hanger 14.

A sleeve-shaped adapter 30 as shown in FIG. 4 may then be installed overthe protruding end of the tube 20. The adaptor 30 preferablyincorporates a long internal taper 36 as shown in FIG. 5 that allowseasy installation over the tube 20 without generating prohibitivebending loads, and also provides precision final centralization of thetube 20 as it exits the adapter 30. This feature counteracts the lateraloffset and some of the angular misalignment. The adapter 30 may then betightened, creating a metal seal with the outer housing 18. This staticmetal-to-metal seal between the adapter 30 and the housing 18 may besupplemented with an elastomeric, e.g., rubber O-ring seal 38, as shownin FIG. 5.

In order to allow tightening of the adapter, it may first be necessaryto apply a side load to the threaded gland 22 using an alignment tool 82to straighten the threaded gland into sufficient lateral and angularalignment with the adapter 30.

As shown in FIG. 4A, an alignment tool 82 may be again employed tocorrect any final angular misalignment between the threaded gland 66 andthe adapter 30 by applying a corrective side load, as needed. As theside load is applied, simultaneously the outer threaded gland 66 may betightened to a desired final torque level. The radial penetratorassembly thus forms a conduit with one secured by threaded gland 64 tothe hanger 14, and the opposing end sealed by adapter 30 to the housing18.

Once the penetrator assembly has been installed as shown in FIG. 5, acover flange 52 as shown in FIG. 6 may be installed pressure-tight overthe outer end of the penetrator assembly protruding from the outside ofthe outer body, with a bore in tubing line 12 in fluid communicationwith the tube 20. In one embodiment, this flange 52 is used with aninternal valve 54 as shown in FIG. 6A communicating with the throughpassageway in the tube 20 to control fluid flow to a respective line 12.The flange 52 may be used with an external conduit or tubing 42 throughwhich fluids may be transferred. Static seal 58 may seal the flange 52to the housing 18, while conventional bolts 59 allow the flange to beeasily installed and removed from the wellhead housing. The entire flowcircuit thus desirably employs metal-to-metal seals throughout.

FIG. 6A illustrates one embodiment of the assembly in a testconfiguration. An alternate embodiment may conduct the fluid through thetest flange without using an integral valve. Once the cover flange 52has been placed over the radial penetrator subassembly, the flange ringgasket may be tested to verify pressure integrity. FIG. 6A shows theadapter 30 with an O-ring seal 100, which allows the introduction oftest fluid between the O-ring and the metal gasket 58 through test port101 by removing plug 102. This ensures the sealing integrity of seal 58without introducing test fluid into port 16 via tube 20.

The radial penetrator assembly of the present invention is particularlysuited for providing a desired fluid path between a wellhead housing anda tubular hanger for suspending a tubular string in a well. In otherembodiments, the tubular hanger may be replaced by some type of plug orother inner member which is landed in the central bore of the wellheadhousing and has a port in general alignment with the radial passagewayin the wall of the wellhead housing.

The radial penetrator assembly as disclosed herein preferably includesthree metal-to-metal seals which allow the assembly to be reliablyinstalled, easily removed, and then again installed between the wellheadhousing and the tubular hanger: (1) a radial inner seal energized by thegland 64 sealing between the radially inner end of the tube 20 and thetubular hanger 14, (2) a radially intermediate seal, which optionallymay be supplemented by an elastomeric seal, between the inner portion ofthe adapter 30 and the wellhead housing 18, and finally (3) a radiallyouter metal-to-metal seal energized by the threaded gland 66 sealingbetween the outer end of the adapter 30 and the outer end of theflexible tube 20.

A preferred new design includes an O-ring on the body of the adaptor orgland 30. This allows test fluid to be introduced through the port 101shown in FIG. 6A, thereby allowing a verifiable demonstration that thegasket 58 holds pressure without introducing test fluid into port 16.The user may then be shown that the connection meets all regulations.

While preferred embodiments of the present invention have beenillustrated in detail, it is apparent that other modifications andadaptations of the preferred embodiments will occur to those skilled inthe art. The embodiments shown and described are thus exemplary, andvarious other modifications to the preferred embodiments may be madewhich are within the spirit of the invention. Accordingly, it is to beexpressly understood that such modifications and adaptations are withinthe scope of the present invention, which is defined in the followingclaims.

1. A radial penetrator assembly for sealingly conducting fluid throughthe passageway in a wall of a wellhead housing having a central bore andinto a port in an inner member positioned within the central bore of thewellhead housing, the radial penetrator assembly comprising: a flexibletube extending radially between the passageway in the wellhead housingand sealingly engaging the port in the inner member; a sleeve-shapedadapter extending radially from the wellhead housing and having anadapter bore sealed to the passageway in the wellhead housing; and aradially outer seal between a radially outer portion of the adapter anda radially outer portion of the flexible tube, such that the flexibilityof the tube permits an inner portion axis of the tube to be axiallyoffset or slanted with respect to an outer portion axis of the tube. 2.A radial penetrator assembly as defined in claim 1, wherein the radiallyouter seal is a metal-to-metal seal between an outer sealing surface onthe flexible tube and an inner sealing surface on the adapter.
 3. Aradial penetrator assembly as defined in claim 2, wherein the innersealing surface on the adapter is tapered for sealing with a taperedsurface on the outer seal.
 4. A radial penetrator assembly as defined inclaim 2, wherein the outer sealing surface on the flexible tube issubstantially cylindrical for sealing engagement with a substantiallycylindrical inner surface on the outer seal.
 5. A radial penetratorassembly as defined in claim 1, wherein the inner member comprises atubular hanger for suspending a tubular string in a well, and the portin the tubular hanger is a throughport which extends to an end surfaceof the tubular hanger.
 6. A radial penetrator assembly as defined inclaim 1, wherein the inner member is positioned on a landing shoulder ofthe wellhead housing to be at a selected axial position within thecentral bore of the wellhead housing.
 7. A radial penetrator assembly asdefined in claim 6, further comprising: a radial alignment member forselectively aligning the inner member within the central bore of thewellhead housing.
 8. The radial penetrator assembly as defined in claim1, wherein the wellhead housing has a generally cylindrical bore.
 9. Aradial penetrator assembly as defined in claim 1, wherein the innermember has a generally cylindrical outer diameter.
 10. A radialpenetrator assembly as defined in claim 1, wherein the port in the innermember includes a throughport extending to an end surface of the innermember.
 11. A radial penetrator assembly as defined in claim 10, whereinan axis of the passageway in the wellhead housing is substantiallyaligned with an axis of the end port.
 12. A radial penetrator assemblyas defined in claim 1, wherein the adapter bore is substantially alignedwith the passageway in the wellhead housing.
 13. A radial penetratorassembly as defined in claim 1, wherein the outer member has a generallycylindrical outer surface.
 14. A radial penetrator assembly as definedin claim 1, wherein the flexible tube has a substantially cylindricalouter surface along substantially its axial length.
 15. A radialpenetrator assembly as defined in claim 1, wherein the radially innerend of the flexible tube is removably sealed with the inner member by aninner plug.
 16. A radial penetrator assembly as defined in claim 15,wherein the inner seal is removably secured to the inner members bythreads.
 17. A radial penetrator assembly as described in claim 16,further comprising: an outer seal for sealing between the flexible tubeand the adapter, the outer seal being removably secured to the adapterby threads.
 18. A radial penetrator assembly as defined in claim 1,wherein a radial spacing between a radially inner end of the flexibletube and a radially outer end of the flexible tube is in excess of about30% greater than a radial spacing between a radially inner end of theflexible tube and a radially outer end of the passageway in the wall ofthe outer member.
 19. The radial penetrator assembly as defined in claim1, further comprising: a flange assembly sealed to the outer housing andhaving a port in fluid communication with a cavity in the cover flangewhich receives an outer portion at the adapter.
 20. A radial penetratorassembly for sealingly conducting fluid through the passageway in a wallof a wellhead housing having a generally cylindrical bore and into aport in a tubular hanger positioned within the central bore of thewellhead housing for suspending a tubular string in a well, the radialpenetrator assembly comprising: a flexible tube extending radiallybetween the passageway in the wellhead housing and the port in the innermember; a sleeve-shaped adapter extending radially from the wellheadhousing and having an adapter bore sealed to the passageway in thewellhead housing; a radially outer metal-to-metal seal between aradially outer portion of the adapter and radially outer portion of theflexible tube, such that the flexibility of the tube permits an innerportion axis of the tube to be axially offset or slanted with respect toan outer portion axis of the tube.
 21. A radial penetrator assembly asdefined in claim 20, wherein the tubular hanger is positioned on alanding shoulder of the wellhead housing to be at a selected axialposition within the central bore of the wellhead housing and isrotationally aligned with the outer member by an alignment member.
 22. Aradial penetrator assembly as defined in claim 21, further comprising: arotational alignment member for rotationally aligning the tubular hangerwithin the central bore of the wellhead housing.
 23. A radial penetratorassembly as defined in claim 10, further comprising: an outer seal forsealing with the outer sealing surface on the flexible tube and theinner sealing surface on the adapter
 24. A radial penetrator assembly asdefined in claim 23, wherein the inner member comprises a tubular hangerfor suspending a tubular string in a well and the port in the tubinghanger is a throughport which extends to an end surface of the tubularhanger.
 25. A radial penetrator assembly as defined in claim 23, whereinthe outer sealing surface on the flexible tube is substantiallycylindrical for sealing engagement with a substantially cylindricalinner surface on the outer plug.
 26. A radial penetrator assembly asdefined in claim 20, wherein the port in the inner member includes athroughport extending to an end surface of the inner member.
 27. Aradial penetrator assembly as defined in claim 20, wherein an axis ofthe passageway in the wellhead housing is substantially aligned with anaxis of the end port.
 28. A radial penetrator assembly as defined inclaim 20, wherein the adapter bore is substantially aligned with thepassageway in the wellhead housing.
 29. A radial penetrator assembly asdefined in claim 20, wherein the radially inner end of the flexible tubeis removably sealed with the tubular hanger by an inner seal.
 30. Aradial penetrator assembly as defined in claim 29, wherein the innerseal is removably connected to the tubular hanger by threads.
 31. Aradial penetrator assembly as defined in claim 29, further comprising:an outer seal for sealing between the flexible tube and the adapter, theouter seal being removably sealed to the adapter by threads.
 32. Aradial penetrator assembly as defined in claim 20, wherein a radialspacing between a radially inner end at the flexible tube and a radiallyouter end of the flexible tube is in excess of about 30% greater than aradially spaced between a radially inner end of the flexible tube and aradially outer end of the passageway in the wall of the outer member.33. A radial penetrator assembly as defined in claim 20, furthercomprising: a flange removably sealed to the outer housing and having aport in fluid communication with a cavity in the flange which receivesan outer portion of the adapter.
 34. A method of sealingly conductingfluid through the passageway in a wall of a wellhead housing having acentral bore and into a port in an inner member positioned within thecentral bore of the wellhead housing, the method comprising: radiallyextending a flexible tube between the passageway in the wellhead housingand the port in the inner member; providing a sleeve-shaped adapterextending radially from the wellhead housing and having an adapter boresealed to the passageway in the wellhead housing; and forming a radiallyouter seal between a radially outer portion of the adapter and radiallyouter portion of the flexible tube, such that the flexibility of thetube permits an inner portion axis of the tube to be axially offset orslanted with respect to an outer portion axis of the tube.
 35. A methodas defined in claim 34, wherein the radially outer seal is ametal-to-metal seal formed between an outer sealing surface on theflexible tube and an inner sealing surface on the adapter.
 36. A methodas defined in claim 34, wherein the inner member is positioned on alanding shoulder of the wellhead housing to be at a selected axialposition within the central bore of the wellhead housing.
 37. A methodas defined in claim 36, further comprising: providing a rotationalalignment member for rotationally aligning the inner member within thecentral bore of the wellhead housing.
 38. A method as defined in claim34, further comprising: providing an outer seal for sealing with theouter sealing surface on the flexible tube and the inner sealing surfaceon the adapter.
 39. A method as defined in claim 30, further comprising:tapering the inner sealing surface on the adapter for sealing engagementwith a tapered surface on the outer seal.
 40. A method as defined inclaim 38, wherein the outer sealing surface on the flexible tube issubstantially cylindrical for sealing engagement with a substantiallycylindrical inner surface on the outer seal.
 41. A method as defined inclaim 34, wherein an axis of the passageway in the wellhead housing issubstantially aligned with an axis of the end port.
 42. A method asdefined in claim 34, wherein the radially inner end of the flexible tubeis removably sealed with the inner member by an inner seal.
 43. A methodas defined in claim 34, wherein an inner seal is removably sealed to theinner member by threads.
 44. A method as defined in claim 43, furthercomprising: providing an outer seal for sealing between the flexibletube and the adapter, the outer seal being removably secured to theadapter by threads.
 45. A method as defined in claim 34, wherein aradial spacing between a radially inner end of the flexible tube and aradially outer end of the flexible tube is in excess of about 30%greater than a radial spacing between a radially inner end of theflexible tube and a radially outer end of the passageway in the wall ofthe outer member.
 46. A method as defined in claim 34, furthercomprising: removably sealing a flange to the outer housing and having aport in fluid communication with a cavity in the flange which receivesan outer portion of the adapter.
 47. A method as defined in claim 34,wherein the port in the inner member includes a throughport extending toan end surface of the inner member.
 48. A method as defined in claim 34,wherein test fluid is introduced to verify holding of a selected workingpressure.